Year
2003
Abstract
One of the main tasks for the Safeguards Analytical Laboratory (SAL) is the analysis of the isotopic and concentration of U and Pu in samples taken by Safeguard inspectors either for verification of declared values on nuclear material or for the environmental sample program in the search for undeclared activities. For the analysis of these samples the Agency has established three mass spectrometry laboratories within SAL. Two of these are TIMS laboratories and one is a Secondary Ionisation Mass Spectrometry (SIMS) laboratory. The technical demands for the TIMS laboratories vary for the different types of samples. The main issue in connection with the nuclear inspection samples is to establish the highest degree of confidence in the results by rigorous quality control and timeliness at approximately 5000 measurement per year. The nuclear TIMS laboratory at SAL was recently completely renovated and optimised for these analyses. An overview on the issues of QC control, timeliness and optimisation are addressed in this paper. The environmental swipe samples, on which dust particles are collected, are typically analysed by both particle analyses by SIMS and so-called bulk analysis using TIMS. The bulk measurement can detect low levels of Pu, typically in the lower fg range. The detection limit of Pu in these bulk samples is a critical factor and the IAEA has engaged in several projects to enhance this detection limit. The isotopic Pu signature, in particular the 240Pu/239Pu and the 241Pu/239Pu ratios, are important because it determines the presence of weapon grade material and also contains information about the origin of the material. The present status and the program for further improvements in the analysis of fg amounts of Pu is presented.